Abstract: Disclosed is an OLT optical transmission system, which includes: an OLT optical transceiver module configured to send downlink light to a first single-mode waveguide module and receive uplink light input by a multimode waveguide module, the first single-mode waveguide module configured to send the received downlink light to a beam splitting/combination module; the beam splitting/combination module configured to perform beam splitting on the received downlink light to obtain multiple beams of downlink light, send the multiple beams of downlink light to corresponding second single-mode waveguide modules respectively, perform beam combination on multiple beams of received uplink light to obtain one beam of uplink light and send the combined uplink light to the multimode waveguide module; the second single-mode waveguide modules configured to send the multiple beams of received downlink light to multiple corresponding ODNs and send the multiple beams of received uplink light to the beam splitting/combination modu

Abstract: Disclosed are a method and device for transmitting optical signals. The method comprises: if there is Raman crosstalk between a first optical network system and a coexistence system, an upstream wavelength band of the first optical network system is set outside a range with an upstream wavelength band of the coexistence system being a center and with an impact intensity of the Raman crosstalk being a radius, and a downstream wavelength band of the first optical network system is set outside a range with the downstream wavelength band of the coexistence system being a center and with the impact intensity of the Raman crosstalk being a radius; and optical signals are transmitted by using the upstream wavelength band of the first optical network system and the downstream wavelength band of the first optical network system. The disclosure can avoid interference and improve signal quality.

Abstract: Disclosed are a method for prolonging the transmission distance of a passive optical network system and an optical line terminal. The method includes: acquiring each EDC tap coefficient corresponding to each ONU; and according to the each EDC tap coefficient corresponding to the each ONU, performing dispersion compensation respectively on an uplink signal sent from the each ONU. Thus the dispersion suffered by ONUs at different transmission distances can be pertinently compensated, so that the transmission distance of the system can be effectively prolonged.

Abstract: A method for amplifying and dynamically adjusting an optical signal is provided in the present invention, which includes: a first optical tap splitting out a small part of the optical signal, which is converted into an electric signal via a first optical detector and is then output to a high speed gain control circuit, in proportion from an uplink burst optical signal, and outputting a remainder of the optical signal to an optical amplifier; the high speed gain control circuit dynamically adjusting the control signal loaded on the optical amplifier according to the input electric signal which varies with uplink burst slots; and the optical amplifier dynamically adjusting a gain value according to the loaded control signal to make peak powers of the output uplink optical signals in different burst slots equal, thus achieving output power equalization.

Abstract: Disclosed are a method and device for transmitting optical signals. The method comprises: if there is Raman crosstalk between a first optical network system and a coexistence system, an upstream wavelength band of the first optical network system is set outside a range with an upstream wavelength band of the coexistence system being a center and with an impact intensity of the Raman crosstalk being a radius, and a downstream wavelength band of the first optical network system is set outside a range with the downstream wavelength band of the coexistence system being a center and with the impact intensity of the Raman crosstalk being a radius; and optical signals are transmitted by using the upstream wavelength band of the first optical network system and the downstream wavelength band of the first optical network system. The disclosure can avoid interference and improve signal quality.

Abstract: A method for amplifying and dynamically adjusting an optical signal is provided in the present invention, which includes: a first optical tap splitting out a small part of the optical signal, which is converted into an electric signal via a first optical detector and is then output to a high speed gain control circuit, in proportion from an uplink burst optical signal, and outputting a remainder of the optical signal to an optical amplifier; the high speed gain control circuit dynamically adjusting the control signal loaded on the optical amplifier according to the input electric signal which varies with uplink burst slots; and the optical amplifier dynamically adjusting a gain value according to the loaded control signal to make peak powers of the output uplink optical signals in different burst slots equal, thus achieving output power equalization.